Astronomers found the asteroid - now labeled ZLAF9B2 - Saturday morning, hours before closest approach. Trajectory models, observer reports and a video all suggest it struck Earth's atmosphere over South Africa on Saturday.

A small asteroid discovered on Saturday morning, June 2, 2018, surprised astronomers when its trajectory suggested it would pass very, very close to Earth just hours after being detected. The object has been given the temporary designation of ZLAF9B2. There are reports of sightings of a bright meteor, as well as a video that may be related to the event, from Barend Swanepoel in South Africa. He reports the video (see below) as being:

This space rock had an estimated size of only 10-16 feet (3 to 5 meters) in diameter. If it struck (and sometimes they do, and meteorite pieces are found), it was too small to cause serious damages. In contrast, the impressive meteor seen over Chelyabinsk, Russia, in February, 2013 was an estimated 60 feet wide (20 meters). It broke windows in six Russian cities and caused more than 1,500 people to seek medical attention, mostly due to injuries from flying glass. The June 2 asteroid wasn't big enough to do anything like that, but it was big enough to produce a spectacular, very bright meteor.

The 60-inch (1.5-meter) telescope at Mt. Lemmon, which is part of the Catalina Sky Survey in Arizona, was the first to detect asteroid ZLAF9B2 on Saturday morning, according to clocks in North America. Alex Gibbs - principal engineer at the Catalina Sky Survey - posted these images of the object on his Facebook page:

According to NASA/JPL's Center for Near Earth Object Studies (CNEOS), asteroid ZLAF9B2 approached Earth at 27,738 miles per hour (44,640 km per hour).

Models began suggesting that - in case of impact - the asteroid would enter Earth's atmosphere somewhere between Indonesia, the Indian Ocean, or South Africa.

The reported observation of the color yellow in the sighted meteor is of interest because colors in a meteor provide a hint of its composition. Yellow suggest the rock contains sodium, as was also in the 2013 Chelyabinsk meteor.

Small asteroids are difficult to detect. Some space rocks might be dark, and may only reflect a small amount of sunlight as they may already be somewhat close to our planet.

However, as bigger asteroids reflect more light, they are usually detected weeks or months before closest approach.